Detachable scarifier tooth



Nov. `:a 19.26.

F. SNYDER ET AL DETACHABLE SCARIIER TOOTH Filed August 21, 1922 f/v VEN Tono- FRfofR/c/r A? GN YDER M m, m

Patented New. 2, 192%.

STTE

FREDERICK A. SNYDER, 0F ST. PAUL, ANDALVIN- S. JOHNSON, 0F MNNEVAPOLIS,

fait E MINNESOTA.

DETAGHABLE SCARIFIER TOOTH.

Application lecl August 21', 1922. Serial No. 583,285. Y

ln the construction of streets and highways, it is customary to use a machine known as the scarifier, for digging up and loosening the hard top soil preparatory to grading. The digging teeth in such` a machine are formed on the lower ends of upright shanks mounted in the machine frame and arranged at an angle to the ground line. so that they will dig into the top surface as the machine moves along. These teeth are made of steel but the top soil is so hard and the teeth are subjected to such continuous wearing action that they soon become dull and blunted or worn away to such an extent that it is necessary to throw away the remaining part of the tooth and shank and substitute an entire new one in place thereof. This work adds considerably to the upkeep or maintenance of the machine. The object of our invention is to provide a vtooth attachment which, when the shanktooth becomes worn can be substituted for the tooth, provision being made for rigidly mounting the substitute on the shank and holding it as firmlythereon as though it were an integral part of the shank itself.

A further object is to provide a substitute or repair tooth which can be easily and quickly mounted on the shank and when broken or worn can be replaced by another. The invention consists generally in various constructions and combinations all as hereinafter described and pointed out in the claims.

In the accompanying drawings forming part of this specification, Figure l is a detail view showing the shank and tooth of the scarier indicating in dotted lines the original length of the tooth, and in full lines how it is worn down and blunted by contact with the soil. g

Figure 2 shows the shank with the tooth cut off and provision made for clamping theY substitute tooth thereon.

Figure 3 is a detail sectional view showing the manner of mounting the substitute tooth on the shank.

Figure a is a sectional view on the line fr-4; of Figure 3.

in the drawing, 2 represents a scarifying shank, and 3, a tooth formed integrallyi thereon as usual in machines of this type. `We have indicated at 4 how the tooth may be worn by contact with the soil to such an extent that it cannot satisfactorily perform its functions. When a tooth reaches this state, we propose to out it off along the line indicated at 5 in Figure 2. We then provide a transverse groove 6 in preferably the forward longitudinal edge of the shank by filing `or other suitable means, and then we provide a substitute tooth 7 having a boX or housing 8 that is adapted to receive the lower end of the shank, the under surface of the toothbeing preferably flush with the lower end of the shank as indicated in 'Figure 3. r:[he box has a long bearing surface on the shank as indicated, and is prou vided with Va transverse pin 9 upset or headed' at each end and adapted to fit into Vthe 'groove 6 as shown plainly in Figure 3.

thus holding the boX firmly against vertical movement on the shank. On the other side of the shank, a set-screw 10, is provided tapped into the rear wall 11 of the box, and the inner face of said rear wall is beveled as indicated at 12, and adapted` to receive the correspondingly inclined surface of a wedge 18 which is inserted between the rear wall of the box and the rear edge of the shank. This wedge is forced in to its seat until the box is fitted snugly on the shank and the pin 9 clamped firmly in the groove in the forward edge of the shank. W'hen this has been done, the setscrew 10 is tightened and thereupon the wedge will be firmly held in place in the box and by reason of its long bearing surface on the shank, there will be no possibility of twist or oscillation of the box on the shank and the substitute tooth will be as rigid and as firmly held as it would be if it were formed integrally with the shank.

instead of cutting oli the shank of the tooth and mounting the substitute tooth in place of the worn one, we may discard entirely the worn tooth and its shank and provide an entirely new shank, mounting the substitute tooth thereon in the manner described above. in building new machines, new shanks would be furnished, and in repairing old machines we may provide new shanks or cut ed the old ones, as pre ferred. The construction described, allows us to discard the worn tooth, using the l* as fast as the original teeth wear ont they can be cut ofi and the substitute teeth mounted on the shanls with comparatively little,` labor and Aloss of time, when ordinarily it is necessary to withdraw the machine from the work, remove the entire shank and its toot-h and substitnteanother shank and tooth therefor.

@ther ways may be devised foriseouring' Vthe substitute tooth in its position on the shank, but we'prefer the manner shown as it is simpleandeifective'and the-tooth can be inon'ifited'without the use of special tools.

"We claim as our invention: l. A scarifier comprising a tooth formed with upwardly and rearwardly inclined top and 'bottoni 'faces and fhaving at its rear an uprighthollow Vbox-'like portionopen 'at top and bottom, the. internal 'wallsfwhereoi extend from the top of the lrbox-like portion to the upwardly and rearwardly inclined lower face of the tooth, an independent shank Afitted in said hollow ,boxlike yportion with its lower end terminating substantially in the plane of theY lower upwardly inclined face of the tooth and constitnting substantially a continuation thereof, and means for separably connecting' the tooth and shank.

- 2. A scariiier comprising a tooth formed 'of thetooth and extending 'therein from the top thereof to upwardly and rearwardly inclined bottom face of the tooth, and means to prevent thel separation of' the vshanlt and tooth'consisting ofpa recess and projection to fttheren,'said recess and projection being 'located at the jnn'ctionloiz the shank and one 'wall of the box-like member.

In Witness whereof, we have hereuntojset' our handsthis 16th day of August, 1922. FREDERICK A. SNYDER ALVIN S. JOHNSON. 

